Circuit arrangement for a thermally conductive chip assembly and a manufacturing method

Abstract

The circuit arrangement according to the invention provides a substrate ( 10 ), a connecting element ( 18 ) and a chip ( 16 ). The substrate ( 10 ) provides at least a partial metallisation ( 11 ) on its surface. The connecting element ( 18 ) is applied to the metallisation ( 11 ). The chip ( 16 ) is applied to the connecting element ( 18 ). The connecting element ( 18 ) provides an electrically non-conductive glass layer ( 14 ), which is applied directly to the metallisation ( 11 ), and an adhesive layer ( 15 ) between the chip ( 16 ) and the glass layer ( 14 ).

The invention claimed is: 
     
       1. A circuit arrangement comprising:
 a substrate, a connecting element and a chip, 
 wherein the substrate provides on its surface at least a partial metallization, 
 wherein the connecting element is applied to the metallization, 
 wherein the chip is applied to the connecting element, 
 wherein the connecting element provides an electrically non-conductive glass layer which is applied to the metallization, 
 wherein the glass layer extends completely between the chip and the substrate; 
 wherein an adhesive layer is applied between the chip and the glass layer, 
 wherein the metallization extends between the glass layer and the substrate so that the glass layer can be applied to the metallization, 
 wherein a through connection connects the metallization on an upper side of the substrate to a lower side of the substrate in an area of the connecting element, 
 wherein the glass layer is substantially adapted to a surface of the metallization, and a thickness of the glass layer is configured to electrically insulate the chip from the metallization while minimizing a thermal resistance between the chip and the metallization, 
 wherein the metallization is applied to the substrate by a thick-layer process, 
 wherein the metallization provides a maximum surface roughness in a range of 1 μm to 5 μm, and 
 wherein the glass layer provides a maximum average thickness in a range of 5 μm to 12 μm. 
 
     
     
       2. The circuit arrangement according to  claim 1 , wherein the adhesive layer provides a greater specific thermal conductivity than the glass layer by at least a factor of 5. 
     
     
       3. The circuit arrangement according to  claim 1 , wherein specific thermal resistances and thicknesses of the adhesive layer and of the glass layer are such that the thermal resistance of the adhesive layer is less than the thermal resistance of the glass layer by at least a factor of 2. 
     
     
       4. A circuit arrangement, comprising:
 a substrate, a connecting element and a chip, 
 wherein the substrate provides on its surface at least a partial metallization, 
 wherein the connecting element is applied to the metallization, 
 wherein the chip is applied to the connecting element, 
 wherein the connecting element provides an electrically non-conductive glass layer which is applied to the metallization, 
 wherein the glass layer extends completely between the chip and the substrate; 
 wherein an adhesive layer is applied between the chip and the glass layer, 
 wherein the metallization extends between the glass layer and the substrate so that the glass layer can be applied to the metallization, 
 wherein a through connection connects the metallization on an upper side of the substrate to a lower side of the substrate in an area of the connecting element, 
 wherein the glass layer is substantially adapted to a surface of the metallization, and a thickness of the glass layer is configured to electrically insulate the chip from the metallization while minimizing a thermal resistance between the chip and the metallization, 
 wherein the metallization is applied to the substrate by a thin-layer process, and 
 wherein the metallization provides a maximum surface roughness in a range of 0.25 μm to 1 μm. 
 
     
     
       5. The circuit arrangement according to  claim 1 , wherein the glass layer is applied by sintering a glass paste onto the substrate. 
     
     
       6. The circuit arrangement according to  claim 1 , wherein the adhesive layer has a binding agent, the binding agent having an epoxy resin with incorporated metal particles, and
 wherein the adhesive layer is electrically conductive. 
 
     
     
       7. The circuit arrangement according to  claim 1 , wherein the metallization comprises gold or a silver-palladium alloy or a silver-platinum alloy or copper. 
     
     
       8. A method for manufacturing a circuit arrangement with a substrate, a connecting element and a chip, comprising:
 providing at least a partial metallization on the substrate; 
 providing a glass layer on the metallization, wherein the glass layer extends completely between the chip and the substrate, 
 applying an adhesive layer to the glass layer, 
 applying the chip to the adhesive layer, 
 wherein the metallization extends between the glass layer and the substrate so that the glass layer can be applied to the metallization, 
 wherein a through connection connects the metallization on an upper side of the substrate to a lower side of the substrate in an area of the connecting element, 
 wherein the glass layer is substantially adapted to a surface of the metallization, and a thickness of the glass layer is configured to electrically insulate the chip from the metallization while minimizing a thermal resistance between the chip and the metallization, 
 wherein the metallization is applied to the substrate by a thick-layer process, 
 wherein the thick-layer process achieves a maximum surface roughness of the metallization in a range of 1 μm to 5 μm, and 
 wherein the glass layer is applied in such a manner that is provides a maximum average thickness in a range of 5 μm to 12 μm. 
 
     
     
       9. The method according to  claim 8 , wherein the adhesive layer is applied in such a manner that it provides a greater specific thermal conductivity than the glass layer by at least a factor of 5. 
     
     
       10. The method according to  claim 8 , wherein the specific thermal resistances and thicknesses of the adhesive layer and of the glass layer are selected in such a manner that the thermal resistance of the adhesive layer is less than the thermal resistance of the glass layer by at least a factor 2. 
     
     
       11. A method for manufacturing a circuit arrangement with a substrate, a connecting element and a chip, comprising:
 providing at least a partial metallization on the substrate, 
 providing a glass layer on the metallization, wherein the glass layer extends completely between the chip and the substrate, 
 applying an adhesive layer to the glass layer, 
 applying the chip to the adhesive layer, 
 wherein the metallization extends between the glass layer and the substrate so that the glass layer can be applied to the metallization, 
 wherein a through connection connects the metallization on an upper side of the substrate to a lower side of the substrate in an area of the connecting element, 
 wherein the glass layer is substantially adapted to a surface of the metallization, and a thickness of the glass layer is configured to electrically insulate the chip from the metallization while minimizing a thermal resistance between the chip and the metallization, 
 wherein the metallization is applied to the substrate by a thin-layer process, and 
 wherein the thin-layer process achieves a maximum surface roughness of the metallization in a range of 0.25 μm to 1 μm. 
 
     
     
       12. The method according to  claim 8 , wherein the glass layer is applied to the substrate by sintering a glass paste. 
     
     
       13. The method according to  claim 8 , wherein the adhesive layer is manufactured from a binding agent, the binding agent including an epoxy resin with incorporated metal particles, so that the adhesive layer is electrically conductive. 
     
     
       14. The method according to  claim 8 , wherein the metallization is manufactured from gold or a silver-palladium alloy or a silver-platinum alloy or copper. 
     
     
       15. The method according to  claim 13 , wherein the metal particles comprise silver particles.